Every graphic we see online is an image file. Most everything we see printed on paper, plastic or a t-shirt came from an image file. These files come in a variety of formats, and each is optimized for a specific use.
Types of Images :
- Raster Images : These are Pixel based graphics and resolution dependent. Web graphics and photos are examples.
- JPEG (or JPG, Joint Photographic Experts Group).
- GIF (Graphics Interchange Format).
- PNG (Portable Network Graphics).
- TIFF (or TIF, Tagged Image File Format).
- BMP (Bitmap).
- Vector Images : These are curve based graphics (it uses lines and shapes) and resolution independent. Logos and icons are examples.
- SVG (Scalable Vector Graphics).
- PDF (Portable Document Format).
- EPS (Encapsulated PostScript).
- AI (Adobe Illustrator Artwork).
Image formats can be separated into Two broad categories :
lossy compression :
- Lossy compression formats are generally suited for photographs. If we saved an image in a lossy format over and over, the image quality would get progressively worse and worse.
- It does not encode all the information of the file, so when it is recovered into an image, it will not be an exact representation of the original. However, it is able to compress images very effectively compared to lossless formats, as it discards certain information.
- Example of a lossy compression format is JPEG.
- Lossless compression formats are suited for illustrations, drawings and text.
- It will encode all the information from the original, so when the image is decompressed, it will be an exact representation of the original. As there is no loss of information, it is not able to achieve as high a compression as lossy compression, in most cases.
- Examples of lossless image compression is PNG and GIF.
More information :
